United States · 1991–2020

Best time to visit
Sinking Spring.

September leads for comfortable weather in Sinking Spring: typically 24.7°C by day, 12.3°C at night, with 132 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortSeptember

Typical high24.7°C

Typical low12.3°C

Rain in September132 mm

Comfort

September

September · June · May

75climate match

Beach

July

July · August · June

68climate match

Outdoors

May

May · October · April

78climate match

The weakest month is January, scoring 5 against September’s 75 — days reach only 2.7°C, 21° below the 24°C the score treats as ideal.

Month by month

The whole year,
without the guesswork.

The bars show the comfort score. Day and night temperatures come from daily observed highs and lows; rain is the historical monthly estimate.

Jan

52.7° / -6.7°

Feb

54.1° / -6°

Mar

99.2° / -1.6°

Apr

4416.3° / 3.8°

May

7121.9° / 9.6°

Jun

7226.9° / 15°

Jul

5929.6° / 17.7°

Aug

6828.4° / 16.6°

Sep

7524.7° / 12.3°

Oct

5318° / 5.9°

Nov

2411.4° / 0.5°

Dec

55.4° / -3.6°

Monthly climate evidence for Sinking Spring — daylight is calculated from latitude, everything else is measured
Month	Day	Night	Rain	Wet days	Daylight	Comfort	Coverage
January	2.7°C	-6.7°C	69 mm	7.3	9 h 35	5	Strong coverage
February	4.1°C	-6°C	58 mm	6.4	10 h 36	5	Strong coverage
March	9.2°C	-1.6°C	95 mm	7.4	11 h 49	9	Strong coverage
April	16.3°C	3.8°C	84 mm	7	13 h 13	44	Strong coverage
May	21.9°C	9.6°C	90 mm	8.2	14 h 23	71	Strong coverage
June	26.9°C	15°C	125 mm	9	15 h 02	72	Strong coverage
July	29.6°C	17.7°C	121 mm	8.7	14 h 47	59	Strong coverage
August	28.4°C	16.6°C	111 mm	7.7	13 h 46	68	Strong coverage
September	24.7°C	12.3°C	132 mm	7.6	12 h 24	75	Strong coverage
October	18°C	5.9°C	85 mm	6.7	11 h 04	53	Strong coverage
November	11.4°C	0.5°C	77 mm	5.8	9 h 53	24	Strong coverage
December	5.4°C	-3.6°C	93 mm	7.5	9 h 19	5	Strong coverage

Records at BLUE MARSH LAKE, 1978–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	21.1°C15 Jan 1995	-33.9°C21 Jan 1994	62 mm4 Jan 1982	133 mm1990 · driest 0 mm in 2016	48
February	26.7°C22 Feb 2018	-24.4°C6 Feb 1996	66 mm15 Feb 2007	135 mm2008 · driest 3 mm in 2000	47
March	29.4°C31 Mar 1998	-21.1°C8 Mar 2015	84 mm22 Mar 2000	164 mm2011 · driest 9 mm in 1990	47
April	32.2°C23 Apr 1985	-9.4°C7 Apr 1982	77 mm16 Apr 1983	237 mm1983 · driest 2 mm in 2023	47
May	35.0°C31 May 2006	-1.7°C21 May 2002	105 mm6 May 1989	312 mm1989 · driest 2 mm in 2023	48
June	37.8°C12 Jun 1986	1.7°C13 Jun 1980	103 mm7 Jun 1994	241 mm2006 · driest 16 mm in 1986	48
July	39.4°C23 Jul 2011	7.8°C7 Jul 1983	102 mm23 Jul 2013	248 mm2004 · driest 11 mm in 1999	48
August	38.3°C1 Aug 1999	4.4°C29 Aug 1986	115 mm4 Aug 2018	245 mm2018 · driest 9 mm in 1995	48
September	36.1°C3 Sep 1980	-1.1°C28 Sep 1991	124 mm9 Sep 1987	315 mm1999 · driest 8 mm in 2014	48
October	32.8°C3 Oct 1986	-6.1°C31 Oct 1988	153 mm1 Oct 2010	230 mm2010 · driest 1 mm in 2024	47
November	27.2°C1 Nov 2024	-12.2°C23 Nov 2018	66 mm23 Nov 2011	183 mm1983 · driest 0 mm in 1998	48
December	22.8°C30 Dec 1984	-18.9°C26 Dec 1980	90 mm13 Dec 1983	249 mm1983 · driest 0 mm in 1989	48

Typical days per month at BLUE MARSH LAKE, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)	Snow days
January	0	0	26	2	3
February	0	0	24	2	3
March	<1	0	20	3	1
April	3	<1	7	2	<1
May	9	3	<1	2	0
June	21	8	0	3	0
July	28	15	0	3	0
August	27	11	0	3	0
September	15	4	<1	3	0
October	3	<1	4	2	0
November	<1	0	15	2	<1
December	0	0	24	3	1

How often, not how much — every day in BLUE MARSH LAKE’s record sorted by what it was actually like, rather than averaged
Month	Warm & dry days	Wet days	Washouts	Week with 3+ wet days	Daytime mean has ranged
January	<1%	22%	7%	16%	-1.0–5.9°C
February	<1%	23%	8%	16%	1.3–7.5°C
March	7%	23%	9%	24%	6.0–12.8°C
April	23%	25%	10%	22%	13.9–18.8°C
May	51%	28%	12%	31%	19.2–24.4°C
June	68%	29%	12%	26%	25.3–28.5°C
July	73%	27%	12%	26%	27.4–31.5°C
August	75%	24%	10%	19%	26.4–30.2°C
September	68%	23%	11%	19%	22.8–26.5°C
October	31%	21%	8%	14%	16.0–20.4°C
November	6%	20%	8%	13%	9.0–13.9°C
December	<1%	23%	10%	18%	2.4–8.1°C

A warm and dry day reaches 20°C with under 1 mm of rain; a wet day gets 1 mm or more; a washout gets 10 mm or more. The week column is the share of seven-day stretches in that month, across the station’s whole daily record, that contained three or more wet days — the odds a week-long trip is rained on repeatedly, counted rather than modelled. The last column is the 10th to 90th percentile of that month’s daytime average across individual years: a narrow band means the average is what you will get, a wide one means the average is a midpoint between years that felt quite different.

1979Each stripe is one year’s mean temperature against the 45-year average. Warmest: 2006. Coolest: 1992.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 5212342
NOAA station: USC00360785 · BLUE MARSH LAKE
Station distance: 6.1 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 26 usable years
Daylight: Calculated from latitude 40.33°, mid-month, sunrise to sunset including refraction. Not a station measurement.
Important limit: Historical climate is not a forecast. Nearby stations can miss mountains, coasts, and local microclimates.

These places read the same station, so their numbers are identical — distance from BLUE MARSH LAKE is what differs

Whitfield→Womelsdorf→Wernersville→Newmanstown→Swartzville→Robesonia→

Or put two places side by side: Sinking Spring vs Whitfield

Best time to visitSinking Spring.

September

July

May

The whole year,without the guesswork.

Nearby, measured,and named.

Best time to visit
Sinking Spring.

The whole year,
without the guesswork.

Nearby, measured,
and named.